Drowning is one of the leading causes of death for children age 14 and under and 75 percent of children involved in swimming pool accidents are between 1 and 3 years old. One of the most important safety devices for any swimming pool is a pool safety cover to prevent harm to small children and animals venturing into a swimming pool area by inhibiting their access to the water in the pool. Standard performance specifications for pool safety covers are set forth in ASTM F 1346-91 and are intended to reduce the risk of drowning by a child under five years of age. In this regard, pool safety covers are very different from pool liners which merely line the floor and/or walls of the interior of the pool and pool covers whose primary purpose is to prevent debris from entering the pool and not to provide a high level of safety for children under the age of five by inhibiting their access to the water.
Pool safety covers must meet rigorous strength and safety specifications. Thus, for pools having diameters greater than eight feet, the safety cover must be able to support the weight of two adults and a child, i.e., at least 485 pounds. In addition, the safety cover must be designed in such a way that if a child under the age of five were to fall onto the cover neither that child nor another child could slip through any openings that may occur between the safety cover and the side of the pool or gain access to the water. Still further, safety covers must either incorporate a drainage system or have an auxiliary system provided which will drain substantially all standing water from the cover within thirty minutes after cessation of normal rainfall. This is to prevent the formation of water puddles on the upper surface of the pool cover since these puddles can constitute a drowning hazard for small children under five years of age. Finally, a safety cover must be so constructed that any opening in the cover or between the cover edge and the deck surface or coping wall and the top surface of the pool is sufficiently small and strong to prevent the opening from being forced to a size that a small child's head could gain access to the water.
Historically, solid pool covers were made using light gauge polyvinyl chloride (PVC) and were held in place around the pool with weights, most typically water filled bags. These covers, while protecting the pool from debris entering the water during the non-swimming season, sagged, stretched, collected water and became a drowning hazard. Light weight mesh covers were developed to allow water to pass through to avoid puddling while maintaining most of the debris on top and out of the pool water. However, as debris collected on top of the mesh cover, it pressed the cover material into the water and contributed to the accumulation of dirt in the pool. Over time better materials became available but none of these early pool covers could truly be considered “safety” covers until reinforced vinyl and the use of tension straps came into use. There are currently two varieties of safety pool covers, mesh and solid. Both types are anchored to a pool decking with straps that are attached to the cover and which are used to pull the cover taut over the pool. The straps are usually attached to stainless steel compression springs and are coupled to recessed anchors embedded in the deck surface. When the cover is removed, deck anchors which are not already flush with the deck can be screwed down to prevent tripping or toe-stubbing. Mesh covers allow rain and snow to drain through the mesh, avoiding puddling; however, dirt and silt can pass through the webbing and dirty the pool water. Solid pool covers keep the pool free of dirt and silt; however, they are subject to puddling on the surface, necessitating the use of drain panels in the solid cover or small cover pumps to automatically pump accumulated water off the cover.
Referring to FIG. 1, conventional prior art safety pool covers are formed of either a strong mesh fabric or a solid non-porous fabric reinforced by attached webbing strips or straps which extend across the entire length and width of the cover in typically perpendicular crossing patterns across one or both sides of the fabric and extend outwardly from the perimeter of the cover. The cover is held taut over the water surface of a swimming pool by compression springs coupling the outwardly extending straps to anchors embedded in the deck surface surrounding the pool. These covers are normally suspended above the entire water surface and extend beyond the edge of the pool about 12 to 18 inches onto the surrounding deck surface so that, in compliance with ASTM F 1346-91, there are no openings providing access to the water through which children or animals can fall or become lodged. Likewise, in compliance with ASTM F 1346-91, the covers are designed to support the weight of two adults and a child without structural failure. Safety covers are preferably custom made for pools to assure proper fit, although ready made safety covers are often used for pools having conventional shapes and sizes, such as rectangular pools. Prior art safety covers are typically manufactured from sheets of mesh or solid fabric which are cut into appropriately sized pieces for a particular pool, e.g., 3′×3′ or 5′×5′ squares, and then stitched to the typically crisscrossed webbing straps to form a pool cover having the desired shape for covering the particular swimming pool. In all prior art pool safety covers the seams between pieces of fabric and the webbing straps are stitched using thread. It has been found, however, that stitching carries a high risk of failure especially over time as water, chemicals and weather conditions cause the webbing straps and stitching to dry rot or otherwise deteriorate and, ultimately, fail. Accordingly, there is a need for a pool safety cover which meets the specifications of ASTM F 1346-9, which is not subject to deterioration and failure due to water, chemical exposure and/or weather conditions and which does not exhibit the other disadvantages of conventional prior art pool safety covers.